When Johnny Matlock whisks away a cold war secret from under the noses of Berlin's top secret agents, his every move is followed when he returns to England. His girlfriend Paula is kidnapped but her handbag is discovered at the scene of the crime by the aristocratic private eye, Duke Martin. Inside it he discovers the secret formula that the agents are searching for and tracks down her sister Paula. As Johnny grows frantic for the safe return of his girlfriend, Duke Martin plays a deadly game of double bluff with the enemy agents.
Tom Conway
as Tom Martin
Michael Balfour
as Barney
Honor Blackman
as Paula Grant / Paula Jackson
Brian Worth
as Johnny Matlock
Bruce Seton
as Webb
Freddie Mills
as Pat
Alexander Gauge
as MacAllister
John Horsley
as Michael Matlock
Paddy Webster
as Diane Grant
John Colicos
as First Kidnapper
Larry Taylor
as Second Kidnapper
Arthur Lowe
as Mitchell
